Egr, manifold, map, maf replacement swap change !!!!!
... So I finally decided to go all out and try do some thing about my 1.9 jtdm running like a bag of poo, so I thought I'd report my findings to the forum exactly what I did and how I found the easy way round doing it.
New EGR valve and partial blank gaskets.
New intake manifold + cleaning of intake ports.
New map sensor + maf sensor clean.
EGR VALVE: I'm sure many of us have done this buy now and probably more than once, I purchased a new pierburg unit from gsf car parts and sourced the gaskets from eBay, this is about as straight forward job as you can get two big 13mm hex nuts that connect it to the exhaust outlet pipe and 4 x 10mm nuts that connect it to the manifold (not forgetting the 2 x 10mm nuts that hold the support bracket for the engine cover. You can literally do this job in under 30 minute. I've cleaned my unit so many times and it makes the car run better for about 2 days then the usual rough idle returns low torque and power ect. Doing a bit of research I'm led to believe its not the dirt that's causes the major issue it's the electronic side of the valve which gives up, fails to open and close the actuator valve properly and causes excess clogging and registers the ECU fault so if you start having EGR problems I'd be tempted just to replace it straight away with a premium quality unit and prevent going in circles thinking cleaning out the dirt is a fix.
MAP + MAF SENSORS: Firstly for those who don't know the difference the MAP (manifold absaloute pressure) sensor is small Bosch sensor held in by one screw in the back of the intake manifold and more often than not is clogged with the same crap as your EGR and Manifold simple to remove simple to clean although looks fragile so an old toothbrush and degreaser will suffice. The MAF (mass airflow) sensor is large and conical located between the large black intake pipes yet again easy to remove and clean. I purchased maf sensor cleaner from eBay. Be prepared to replace the circlips as these factory ones are near impossible to reuse. Beings my car has over 100k now I chose to replace these sensors with new ones.
INTAKE MANIFOLD: Reading the step through guides about sounds a daunting job but if your patient and have half a brain this is doable in 6-7 hours. Firstly identify wether you have the older all alloy type manifold or the later half alloy half plastic type, on the later type the plastic part can be removed very easily allowing the internal part of the manifold to be cleaned this also aids installation. I'm not going to do a step by step walk through but maybe just a few tips and good avoidances and what's tricky.
1, It was remarkably easy to hold the cambelt in place using two of the housing bolts in the fuel pump pulley, put the car in gear and jolt it forward/or back till the holes are at about 11 o'clock and 2 o'clock and make sure you use both holes not just one. Then 3 12mm lock nuts on the reverse of the fuel pump hold it on to the engine casing to studs and the big 22mm will free it from the pulley drive and a light tap will slide it out of position ... Now for me the tricky bit was you have to remove the bottom stud from the engine casing to make way for the manifold to slide off, tightening one of the M8 nuts up fully and then undoing it should remove it. Getting the nut back off the stud is anyone's guess and a potential thread stripper !!!! I had a new stud and nut ready for the sake of £3.
2, The actuator at the bottom of the manifold is quite bulky, has the oil filter attached and, it's bracket .. By far the hardest piece to remove as you'll need to separate the filter housing from the bracket, And the bracket from the manifold. This is we're the later manifold is amazing !!! On installation or removal separate the 3 manifold pieces, the plastic manifold part from the alloy and take off the throttle body housing (very easy !!!) and take the parts off separately and easily.... On installation slide the alloy part (with actuator attached remembering to plug in connector) over the the studs with new gasket with this sitting in place you can easily refit the oil filter housing bracket then the filter itself, the key here is "room to play with" then just refit the plastic part of the manifold and throttle housing.
* perhaps the reason for the manifold upgrade was the ability to split it apart and clean, not to mention separating the bits on removal and installation. I only found this out on installation so I'm unsure if by separating the manifold you could squeeze it past the fuel pump stud without removal !!! I can only assume the alloy one piece manifold if a pain all round.
* I also didn't drain any coolant on the later type manifold and didnt seem to loose or leak any into the cylinders.
CLEAN EVERYTHING WHILE YOU HAVE IT IN PIECES, YOU CAN EVEN GET TO THE INTAKE PORTS WHICH WILL BE CLOGGED WITH DIRT AND GREASE, AND THE THROTTLE BODY TO MAKE SURE IT SEALS PROPERLY TO THE HOUSING AND THE BUTTERFLY VALVE SEALS (gasket required for housing).
.... Anyway my car runs like new, ticks over like a petrol engine, no excess smoke, more power and response, starts on the button ... Well worth the time and money spent.